1. Field of the Invention
The present invention relates to an edger for trimming an edge of a grassland such as a grassy lawn adjacent to a pavement, building or the like.
2. Description of the Prior Art
In general, an edger of this kind includes a powered cutter device arranged at one side of a traveling body or edger vehicle having wheels, and is controlled by an operator so that an edge of the grassland is trimmed by the edger as he manipulates rearwardly positioned operating handles or controls.
In one conventional edger cutter device driven by a belt, the mechanism for clutching the cutter drive belt also serves to adjust the cutter depth. Accordingly, once the belt has been engaged, the depths of the blade cannot be adjusted.
A conventional edger includes a powered cutting device or blade arranged at the side of the traveling frame or edger vehicle having wheels. It is controlled by an operator so that the edge of the grassland or lawn is trimmed by the cutter blade of the edger as the operator moves the edger frame along the sidewalk or similar hard surface adjacent the lawn.
In the typical edger, it is desirable to have the depth of the cutter blade set to allow the blade to penetrate the ground and roots of the grass so that a clean cut results and the grass and its roots to be removed are easily lifted out of the ground.
One conventional edger includes a cutter blade depth adjusting mechanism which must be set prior to engagement of the blade drive clutch. Once the depth has been set with this edger, the clutch can be engaged but thereafter the depth of the blade can no longer be adjusted until the blade drive is disengaged. Since the operator can most easily determine whether the blade is penetrating the roots while the edger is cutting, it is desirable to be able to adjust the depth of the blade while the blade is engaged. It is desirable therefore to provide an edger wherein the depth of the blade can be adjusted separate from the control for drivingly engaging or disengaging the blade and while the blade is cutting.
Another commercial edger does provide for adjustment of the blade depth separate from engagement of the clutch and while the blade is operating. However, this blade is driven by a centrifugal clutch which couples the shaft carrying the cutter blade directly with the crankshaft of the engine. As this blade encounters obstacles, the shock loads transmitted from the blade to the engine crankshaft can potentially damage the engine.
It is therefore desirable to provide an edger having a blade driven by some means other than a centrifugal clutch so that shock loading encountered by the blade is not transferred to the engine.
One belt driven edger provides for operator adjustment of the blade depth while the blade is being driven. This edger, however, utilizes a detented control having to selectively position the lever in a desired blade depth setting. The depth setting is selected after the drive belt has been engaged. Since the depth setting is selected with the blade running, it continues to run unless the lever is returned to a 0 setting and the belt is disengaged. Accordingly, this machine can continue to operate when the operator leaves the handle or control of the edger, thereby posing a potential safety problem.
It would therefore be desirable to provide an edger wherein the depth of the cutter blade can be adjusted while the blade drive is engaged. Further, it would be desirable to provide a drive means for the blade in a form which does not provide for transfer of shock loads from the blade to the engine crankshaft. Additionally, it would be desirable to provide a control mechanism for maintaining engagement of the blade only when the operator is at the rear of the machine and is actively controlling the drive. More specifically, it would be desirable to provide a bale handle control arrangement for the operator to grasp with one or both hands such that when his grasp on the handle and the control is released, the drive for the cutter blade is disengaged.